This invention relates to improvements in systems for monitoring harmful emissions that may be present in stack gas or ambient air and, in particular, to an improved system which provides monitoring on a near real-time basis and which employs a wet cyclone concentrator in conjunction with appropriate in-line chemical processing to provide a processed sample that may be immediately analyzed for the presence of a predetermined contaminant.
Existing methods for analysis of toxic contaminants in stack gas and in the workplace typically require the collection of air or gas samples through bubblers for an extended period of time. Analysis of the contaminated samples is conducted in a laboratory. The time thus required for collection and analysis can be a dangerous delay when particularly hazardous substances may be present as either a stack gas emission or an air pollutant in the workplace.
Concentrators capable of extracting trace contaminants from air have been proposed and are disclosed in U.S. Pat. Nos. 4,117,714 and 5,011,517, owned by the assignee herein. The air or other gas swirls in the concentrator in intimate contact with a scrubbing liquid such as water and thus impurities in the air are extracted into the water which thereby becomes contaminated and may be withdrawn and analyzed. However, there is no assurance that the substances scrubbed from the air will be in a readily detectable form, or amenable to analysis on a near real-time basis by conventional analyzers.
Furthermore, the need for continuous emission monitors that will operate on a near real-time basis is increasing with the ever-growing governmental requirements for protection of the environment. Also, demilitarization of weapons stockpiles has added to the number of possible contaminants for which such monitoring systems must be adapted.